Effects of prenatal alcohol exposure in mice: influence of an ADH inhibitor and a chronic inhalation study.

In order to examine the effects of an alcohol dehydrogenase inhibitor on the embryotoxic effects of ethanol, pregnant ICR mice were treated with 100 mg/kg pyrazole prior to ethanol injection. I.p. treatment with 2 or 4 g/kg ethanol on day 7 of gestation increased the prenatal mortality rate and produced external and skeletal malformations in the offspring, and the embryotoxic effects were potentiated by pyrazole pretreatment, suggesting that ethanol rather than its metabolites is mainly responsible for the embryotoxicity. In the second experiment, we housed pregnant mice in an ethanol-vapor box for 3 or 6 days in order to examine the effects of prolonged low level exposure to alcohol. The maternal blood alcohol concentration was maintained approximately 0.03 mg/mL during inhalation. The inhalation treatment with ethanol increased the prenatal mortality rate, although teratogenicity was not shown.